Brandy brought the harassing messages she had been receiving on her cell phone to her school’s attention before Thanksgiving, Melissa Tortorici, communications director for the Texas City Independent School District, told InsideEdition.com.

An investigation found that the messages were being sent through an untraceable app and authorities encouraged Brandy to change her phone number, she said.

School officials are also “very concerned” for students and are monitoring them closely, authorities said.

“We are mourning the loss of a wonderful young lady,” Superintendent Dr. Cynthia Lusignolo said. “We are trying to take care of our students’ needs on campus as they grieve. Our thoughts and prayers are with Brandy’s family and friends. We appreciate the outpouring of support we have had in helping us take care of her teachers’ and classmates’ needs.”

The hallways of Texas City High School of have been covered in blue hearts in remembrance of the girl with the “beautiful blue eyes.”

“We are devastated at this news. Our prayers, thoughts and concerns are with her family and friends as they grieve her loss,” Tortorici said in an email. “Brandy was well-liked and friendly... She has touched many people as evident by the outpouring of love from her schoolmates."

Students and teachers have also written letters to express their feelings about Brandy to her family, she said.

A prayer vigil in Brandy’s memory has been planned that will take place in the school’s parking lot at 6:30 p.m. Friday.